Silencer



May 27, 1941.

B. cs. BROWN SILENCER Filed Aug. '24, 1936 2 Sheets-Sheet 1 May 27, 1941 B. G. BROWN SILENCER Filed Aug. 24, 1936 2 Sheets-Sheet 2 wto'mup Patented May 27, 1941 UNITED'STATES PATENT OFFICE SILENCER Benjamin Gm. Brown, rum, Micln, assignor to General Motors Corporation, Detroit, Mich., a corporation of Delaware Application August 24, 1936, Serial No. 97,494

3 Claims. (Cl. 181-48) This invention has to do with silencers and has for its principal object to provide a unit which consists of an air cleaner of the liquid bath type and a silencer of the resonator type so constructed and assembled that it may be installed on an internal combustion engine carburetor which is so located that little head room is available.

For a better understanding of the nature and objects of this invention, referenceis made to the following specification wherein there are described the preferred embodiment of the invention which are illustrated in the accompanying drawings.

Cir

materially from the air cleaner shown in Figure 1 I of the Kamrath applicationSerial No. 740,420 which was filed on August 18, 1934. In each unit, there is included an annular receptacular body 10 which is filled with a suitable liquid, such as oil, to about the level of the bead l I when the unit is in use. Within the body Ill, between its tubularinner wall 12, which constitutes the air outlet duct oi the unit, and its cylindrical outer wall 13, there is disposed a hollow annular member I5 which is filled with a suitable filter medium it, such as that disclosed in the Webb application Serial No.

98,556 which was filed on August 29, 1936. In cylindrical outer wall 13 or the body It, just below its upper edge, there are formed two rings of air inlet orifices l4 0! which those throughout about one-third of the circumierence of the body are shielded by a baflle 23 whose lower? edge is securedtothewall I 3.

In the lower wall of the member 15, there are provided a ring of air inlet orifices l1 and a ring ,0! liquid discharge orifices It. In the upper wall of the member l5, there is provided a ring of air outlet orifices l9. The member I5 is supported on the upper ends of the inner and outer walls of the body Ill throughthe intermediaries-oi an inwardly projecting bead 29 on its inner wall and an outwardly projecting flange 2| on an upwardLv projecting extension of its outer wall.

The outer and bottom walls of the member 15 are spaced, respectively, from the outer wall 13 and above the level of the liquid in the bottom of the body ill to define a passage 22-through which air may travel from the air inlet orifices 14 over the surface of the liquid to the orifices l1 in the bottom of the member I5.

The cover 24 of the unit which is shown in Figure 1 is a hollow member whose outer edge is seated on the flange 2| on the upwardly projecting .'extension of the outer wall of the member 15 and closes the upper end of the latter. The cover 24 consists of a member 25 which is shaped like an inverted cup and a member 25, in which there is formed an orifice 21 which is coaxial with the tubular member l2, joined at its outer edge to the lower edge of the side wall of the member 25 and spaced from the upper wall of the member l5 to define with it a passage 28 through which air may travel from the orifices l9 into the upper end of the tubular member l2.

The interior of the cover 24 is divided into upper and lower compartments 29 and 30 by a partition 3| whose outer edge is joined to the side wall of the member 25. In the partition 31 there is formed an orifice 32 which is coaxial with and of smaller diameter than the orifice 21 in the member 26. The orifice 32 is encircled by a tube 33 which extends through the compartment 30 and. terminates flush with the portion of the member 26 which encircles the orifice 21, and establishes communication between the compartment 29 which constitutes a resonance chamber and the passage 29 independently of the compartment 30. The orifice 21 in the member 26 is encircled by a tube 34 which extends into the compartment 30 but terminates short of the partition 3| and is radially spaced from the tube 33' not differ materially from the cover 24 of the,

unit shown in Figure 1 except in that the partition 3| and the tube 34 have been omitted and the orifice 40 in the member 4| which, of course, corresponds to the member 26 is of smaller dithe air inlet tubes of the carburetors.

ameter than the orifice 21-and encircled by a tube 42 which projects into and is radially spaced from the tubular member [2; a

The bodies I0, the annular members and the covers 24 and 39 of the units shown in Figures 1 and 3 are secured together with the annular members clamped between the bodies and the covers but are, of course, separable one from the others when the elements of thesecuring means, which is designated by the reference character 43 in Figures 1 and 2 and the reference character 44 in Figur 3, are disengaged.

The units shown in the drawings were designed 'for installation on internal combustion engine downdraft carburetors with the lower extremities of the tubular members l2 telescoped around When one of the units is so installed and the engin is operating, air is drawn into the orifices l4, and successively, through the passage 22, the annular member l5 and the passage 28 (or the corresponding passage in the unit shown in Figure 3) into the upper end of the tubular member l2 In the course-of its passage between the orifices i4 and the air outlet orifices IS in the mem ber l5 the air is freed of foreign matter in a manner that requires no description. The resonators 29--33 and 363835-21 incorporated in the unit shown in Figure 1 and the single compound resonator incorporated in the unit shown in Figure 3 are so tuned in the manner set forth in the Wilson application Serial No. 470,700 which was filed on July '25, 1930, and the corresponding foreign patents, viz., Canadian Patent No. 348,037, British Patent No. 391,180, French Patent No. 720,611, and Italian Patent No. 300,037, that they respond to and attenuate by resonance sound waves which issue from the air inlet tube of the carburetor and are of such frequency and intensity that they are objectionable. Thus the units serve both to clean the air which enters the carburetor and the cylinders of, the engine on which they are installed and to silence the intake of the engine.

I claim:

1. A silencing element which includes a tube through which gases and sound waves travel, a hollow cap with an orifice in its inner wall disposed over one end of the tube, a partitionwhich subdivides the hollow cap lengthwise into two chambers, an orifice in the partition, a tubular element which encircles the second-mentioned orifice and projects toward but is spaced from the boundary of the first-mentioned orifice, and an aperture between the hollow cap and the tube through which the latter communicates with the atmosphere.

2. 'A silencing element which includes a tube through which gases and sound waves travel, a hollow cap with an orifice in its inner wall disposed over but spaced from one end of the tube to define therewith an aperture through which the tube communicates with the atmosphere, a partition which subdivides the hollow cap lengthwise into two chambers,'an orifice in the partition, a tubular element which encircles the second-mentioned orifice and extends toward but is spaced from the boundry of the first-mentioned orifice, and a partition in which there is an orifice which subdivides the chamber into which the tubular element extends into intercommunicating compartments.

3. A silencing element in which there is included a tubular member through which gases and sound waves travel, a hollow cap in whose inner wall there is an orifice disposed over an end of the tubular member, a tubular member which encircles the orifice and is telescoped within and radially spaced from the first-specified tubular member, and an aperture between the hollow cap and the first mentioned tubular member through which the latter communicates with the atmosphere.

BENJAMIN GRATZ BROWN.

v M CERTIFICATE OF CQRRECTION.- v I atent No-."2,2l|.5,' 082. I m 27, 19m.

' L ENJAMIN GRATZ BROWN.

Itishereby certifie djfliet error appears in the printed specification )f t he above numbered pater it 'i'equiririg correction as foilowai'Page 1, first wlumn, line 1, after the word "with'f inge'rj; air c'leai lera and; line 11, #or "embodiment read --e| nbod1me nts and thet 1556 3am Letters Patent mould be read with. thie cbrreetion therei x l the sanie'may confo rm to the recordof the case inthe Patent CIT 196.:

Signed and sealed this th da of Au qst, APD'. 19m.

Henry Van Arsdele,

(Seal) Aet 'ing. Commis siorger of Patents.

. a I CERTIFICATE oncoanEcnom v atent No -2,2L|.3',' 08 2".-

I my 27,1'9h1;v g VBENJAHIN GRATZ BROWN;

Itis here by certified: chat error appears 111 the fi'rinted specification )f t he above nwnbercd p aceh t feqizirizig ccrl 'ecti'on as foilowsz Page 1,'first blumn, lice 1, after :Ii'e word "Mi 12h! zinger? 'a 11 'clea1"1ers and"; line 11, For "embo dimenfi'f read --em bo d1me r;ts]--'- that Letters Patent .ihould be re ad w: 1;h." th:i. s cbrrection theri ri -'th'a;t'-the same-mayconform to the record-of the cas in-th Patent 'Offi c'e Signed and sealed this 5th-daly or-Au' qst, A., D 19m.

I Henry VanAisdi-e, (Seal) Acting. .Commis sicme r of Patents, 

